Vertically integrated storage

ABSTRACT

Various systems, methods, apparatuses, and computer-readable media for accessing a storage device are described. Techniques are described for vertically integrating the various software functions and hardware functions for accessing storage hardware. In some embodiments, the system is implemented using non-volatile memory.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional PatentApplication Ser. No. 61/799,023, filed Mar. 15, 2013 and entitled“VERTICALLY INTEGRATED STORAGE,” U.S. Provisional Patent ApplicationSer. No. 61/798,754, filed Mar. 15, 2013 and entitled “HIGH DENSITYSERVER STORAGE UNIT,” U.S. Provisional Patent Application Ser. No.61/794,647, filed Mar. 15, 2013 and entitled “APPARATUS AND METHOD FORTRANSLATION FROM MULTI-DIMENSIONAL TO LINEAR ADDRESS SPACE IN STORAGE,”U.S. Provisional Patent Application Ser. No. 61/788,613, filed Mar. 15,2013 and entitled “COMPRESSOR RESOURCES FOR HIGH DENSITY STORAGE UNITS,”U.S. Provisional Patent Application Ser. No. 61/793,141, filed Mar. 15,2013 and entitled “MASS STORAGE DEVICE AND METHOD OF OPERATING THE SAMETO BACK UP DATA STORED IN VOLATILE MEMORY,” and U.S. Provisional PatentApplication Ser. No. 61/793,591, filed Mar. 15, 2013 and entitled “MASSSTORAGE DEVICE AND METHOD OF OPERATING THE SAME TO STORE PARITY DATA,”which are incorporated by reference herein in their entirety for allpurposes.

BACKGROUND

Aspects of the disclosure relate to computing and communicationtechnologies. In particular, aspects of the disclosure relate tosystems, methods, apparatuses, and computer-readable media for improvingperformance of storage devices.

Storage devices for enterprise systems require massive storage capacity.Additionally, storage solutions for enterprise systems requiresophisticated storage systems for reliability, robustness, faulttolerance, maximizing storage capacity, minimizing power consumption,and reducing latency. Various storage industry players have specializedin specific aspects of these storage systems in a segmented mannerproviding piecemeal solutions. Combining these various segmentedsolutions results into a clunky storage solution that is less than thesum of its parts and significantly underperforms across the board.

The segmentation and underperformance of the available solutions todayresults in a significant deterrent in adaptation of newer storagetechnologies, such as solid-state devices (SSD). Traditionally,enterprise systems have been implemented using media such as hard diskdrives (HDD) that retain data while the power is turned off. Hard diskdrives are data storage devices, used for storing and retrieving digitalinformation, that use rapidly rotating disks. An HDD consists of one ormore rigid (“hard”) rapidly rotating disks (platters) with magneticheads arranged on a moving actuator arm to read and write data to thedisk surfaces. Due to moving parts, HDDs are inherently slow in terms ofservicing I/O operations compared to the number of storage accessrequests the processor running the software stack can service during thesame time. In the past, since the HDDs were significantly slower thanthe processors, the inefficiencies in the software stack running on theprocessor were both hidden and non-consequential to the speed of theentire system. However, with newer technologies, such as SSDs, that cansupport higher throughput for I/O operations, the inefficiencies in thesoftware architecture is becoming a limiting factor in the adaptation ofsuch newer technologies.

Embodiments of the invention solve this and other problems.

BRIEF SUMMARY

Various systems, methods, apparatuses, and computer-readable media foraccessing a storage medium are described. Techniques are described forvertically integrating the various functions for optimally accessingstorage hardware.

According to some embodiments of the invention, an example storagedevice may include a storage medium comprising non-volatile memory, oneor more processing entities configured to execute a deduplication moduleto detect duplicity of data, and execute a Redundant Array ofIndependent Disks (RAID) module to provide fault tolerance by spreadingdata and parity information across the non-volatile memory. The examplestorage device may be further configured to perform a journalingfunction using a journaling module only once for the deduplicationmodule and the RAID module for an access request to the storage mediumon the storage device, and perform a mapping function using a mappingmodule only once for the deduplication module and the RAID module forthe access request to the storage medium on the storage device. In oneembodiment, a flash translation layer (FTL) module may include thejournaling module and the mapping module. In certain embodiments, thestorage device may be configured to execute a single instance of the FTLmodule for the storage device.

In certain embodiments, the one or more processing units of the storagedevice may be further configured to execute a compression module forcompressing data before storing the data on the storage medium anddecompressing the data after retrieving the data from the storagemedium, wherein the compression module does not have a separatejournaling functionality or separate mapping functionality. In someembodiments, the one or more processing units of the storage device maybe further configured to execute a snapshot and thin provisioningmodule, wherein the snapshot and thin provisioning module does not havea separate journaling functionality or separate mapping functionality.

In other embodiments, the one or more processing units of the storagedevice may be further configured to execute a File System (FS) modulefor providing abstraction to an application for storing, retrieving andupdating files comprising data on the storage medium, wherein the FSmodule does not have a separate journaling functionality or separatemapping functionality. In yet other embodiments, the one or moreprocessing units are further configured to execute an Operating System(OS) module configured to execute on one or more processors, wherein OSmodule does not have a separate journaling functionality or separatemapping functionality.

In some embodiments, the one or more processing units of the storagedevice may be further configured to perform a caching function using acaching module only once for the deduplication module and the RAIDmodule for the access request to the storage medium on the storagedevice. In other embodiments, the one or more processing units arefurther configured to perform a garbage collection function using agarbage collection module only once for the deduplication module and theRAID module for the access request to the storage medium on the storagedevice.

In some embodiments, the mapping function by the mapping module mayperform a translation from a linear address to a physical address forthe access request to the storage device using a multidimensionalmapping, wherein a first dimension of the multidimensional mapping is afile identifier and the second dimension of the multidimensional mappingis a snapshot version.

An example non-transitory computer readable storage medium may includeinstructions executable by a processor to manage access to thenon-volatile memory for the storage medium using a Flash TranslationLayer (FTL) module, detect duplicity of data using a deduplicationmodule, provide fault tolerance by spreading data and parity informationacross the non-volatile memory using a Redundant Array of IndependentDisks (RAID) module, perform a journaling function using a journalingmodule only once for the FTL module, the deduplication module and theRAID module for an access request to the storage medium on the storagedevice, and perform a mapping function using a mapping module only oncefor the FTL module, the deduplication module and the RAID module for theaccess request to the storage medium on the storage device. In someembodiments, the instructions are part of a single executable binary.

In certain embodiments, the non-transitory computer readable storagemedium further includes instructions to compress data only once for astore access request and decompress data only once for a read accessrequest. In other embodiments, the non-transitory computer readablestorage medium further includes instructions to perform caching functiononly once for the access request to the storage medium on the storagedevice. In yet other embodiments, the non-transitory computer readablestorage medium further includes instructions to perform garbagecollection functionality only once for the access request to the storagemedium on the storage device.

An example method for accessing a storage medium on a storage device mayinclude managing access to the non-volatile memory for the storagemedium using a Flash Translation Layer (FTL) module, detecting duplicityof data using a deduplication module, providing fault tolerance byspreading data and parity information across the non-volatile memoryusing a Redundant Array of Independent Disks (RAID) module, performing ajournaling function only once using a journaling module for an accessrequest to the storage medium on the storage device, and performing amapping function only once using a mapping module only once for theaccess request to the storage medium on the storage device.

In certain example embodiments, the method further comprises compressingdata only once if the access request is a store access request anddecompressing data only if the access request is a read access request.In some embodiments, the method further includes performing caching onlyonce for the access request to the storage medium on the storage device.In other embodiments, the method further includes performing garbagecollection functionality only once for the access request to the storagemedium on the storage device. In yet other embodiments, the methodfurther includes performing garbage write combining only once for theaccess request to the storage medium on the storage device.

The foregoing has outlined rather broadly features and technicaladvantages of examples in order that the detailed description thatfollows can be better understood. Additional features and advantageswill be described hereinafter. The conception and specific examplesdisclosed can be readily utilized as a basis for modifying or designingother structures for carrying out the same purposes of the presentdisclosure. Such equivalent constructions do not depart from the spiritand scope of the appended claims. Features which are believed to befeature of the concepts disclosed herein, both as to their organizationand method of operation, together with associated advantages, will bebetter understood from the following description when considered inconnection with the accompanying figures. Each of the figures isprovided for the purpose of illustration and description only and not asa definition of the limits of the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of the disclosure are illustrated by way of example. In theaccompanying figures, like reference numbers indicate similar elements,and:

FIG. 1 illustrates a simplified diagram of a prior art segmentedapproach for accessing storage hardware.

FIG. 2 illustrates a simplified diagram of a vertically integratedapproach for accessing storage hardware.

FIG. 3 illustrates the deduplication module that leverages the commonfunctionality provided by the integrated system.

FIG. 4 illustrates an example flow diagram for performing embodiments ofthe invention.

FIG. 5 illustrates an example of a computing system in which one or moreembodiments may be implemented.

DETAILED DESCRIPTION

Several illustrative embodiments will now be described with respect tothe accompanying drawings, which form a part hereof. While particularembodiments, in which one or more aspects of the disclosure may beimplemented, are described below, other embodiments may be used andvarious modifications may be made without departing from the scope ofthe disclosure or the spirit of the appended claims.

FIG. 1 illustrates a simplified diagram of a segmented approach foraccessing storage hardware. The segmented approach for storage devicesuses a number of stacked software/firmware layers for accessing thestorage hardware from the application layer 116. As shown in FIG. 1, inone implementation, the segmented approach includes the firmware 118associated with the storage device, Redundant Array of Independent Disks(RAID) layer 104, compression layer 106, deduplication layer 108,snapshots/clones/thin provisioning layer 110, file system layer 112, OSinterface layer 114, and application layer 116. The firmware interactingwith the hardware may also act as another layer 102 implementing its ownmanagement 120, caching 122, journaling 124, mapping 126, andwrite/garbage collection 128. In some embodiments, the firmware 118 maybe referred to as the Flash Translation Layer (FTL). The various layersin the stack may be developed by various storage device industryvendors.

In some traditional implementations, the storage hardware for thestorage device may be implemented using several HDDs or SSDs such as 102and 132, from FIG. 1. It should be noted that each of these HDDs or SSDsin prior art systems duplicate the management, caching, journaling,mapping, write/garbage and garbage collection, therefore running severalinstances of the same functionality. Furthermore, the management,caching, journaling, mapping, write/garbage and garbage collection isinternal to the HDDs or SSDs and the storage medium is accessible onlythrough a standardized interface (e.g., SATA, or USB). Therefore, theupper software layers of the software implementing RAID, deduplication,compression, etc. do not have access to such functionality from the HDDor SSD and must duplicate such housekeeping functionality in the upperlayers.

The RAID software/firmware layer 104 provides fault tolerance byspreading the data and parity information across multiple disks orplanes. The compression/decompression layer 106 compresses data allowingfor efficient and faster access of storage medium. The deduplicationlayer 108 generally generates signatures using hash functions for eachcommand that a host issues to the storage device. The deduplicationlayer 108 detects duplication by comparing the current generatedsignature with the maintained ones. In one implementation, thededuplication layer 108 maps the duplicate blocks from the variouslinear addresses to the same physical address, reducing the number ofwrites to storage and using the storage space more efficiently. The filesystem layer 112 provides abstraction for storing, retrieving andupdating files on the storage device. Additionally, the file systemmanages access to data and metadata of the files and available space onthe device. The OS interface layer 114 provides the application layer116 a standardized interface for interacting with the storage device bycalling function calls enabled by the OS interface layer 114.

In addition to their primary roles discussed above, all of the layers ofthe storage stack also perform additional house-keeping routines, suchas maintaining memory, management functions, caching, linear to physicaladdress mapping, garbage collection and journaling of states forprotection against catastrophic events. Many of these functions are alsoperformed in the HDD/SDD (102 and 132). Garbage collection may refer tothe releasing of memory/storage resources no longer needed by the layer.Journaling may refer to logging state before committing the state instate machine. In the event of a catastrophic event, such as a systemcrash or a power failure, journaling may enable the system to recoverfaster and avoid corruption of system state.

Many of these house-keeping routines are duplicated in each layer of thestorage stack, since these house-keeping routines performed by eachlayer are dedicated to that specific layer and isolated from the otherlayers because of the segmented architecture causing significant memory,processing and performance overhead.

Furthermore, for an application from the application layer 116 tocommunicate with the storage device 102, the message (containing data)must pass through seven segmented layers, as shown in FIG. 1, causingduplicated journaling, mapping, compression, caching and garbagecollection functions. The passing of the data message through multiplelayers also requires a number of encapsulation and de-encapsulationsteps that also generates significant overhead.

The interface between each layer also creates bottlenecks. Moreover, theinterface abstracts away details and allows for only limited visibilityto the next layer below and beyond, requiring duplication of functionsin the software stack, such as compression and journaling of state. Forexample, the file system layer 112, the Snapshots/clones thinprovisioning layer 110 and the deduplication layer may all implementcompression algorithms. However, once data is compressed there is verylittle benefit in repeatedly compressing data, resulting in wastedresources, in terms of latency and performance. Therefore, duplicationof functions results in processing and memory overhead considerablydragging down the performance of the system.

Each layer also manages its own mapping structures and algorithms totranslate the message from one layer to another. Mapping operations areexpensive operations, increasing latency of data operations anddegrading the performance of the system even further.

Moreover, the storage stack layers are developed by different vendorsand adhere to various standard bodies. Every layer is developed inisolation from the other layers in the storage stack software vastlyrepeating the same functionality in different manifestationssignificantly increasing the probability of bugs in the system.Additionally, the storage stack layered approach hampers innovation inthe product line, since any innovation that disturbs the interfacesbetween the different layers goes through a complex negotiation processwith the various stake holders, such as the vendors for the differentlayers in the software stack. Furthermore, the performance degradationhas a multiplicative in the layered architecture further exasperatingperformance issues.

FIG. 2 illustrates a simplified diagram of a vertically integratedapproach for accessing storage hardware, according to embodiments of theinvention.

Vertically integrating the various functionalities of the multiplelayers by implementing the functionalities into a single or fewer layerssignificantly increases the ability of the system to providereliability, robustness and fault tolerance functions, while improvingstorage capacity, power consumption, and latency of the overall system.

According to certain embodiments of the invention, the storage devicemay be implemented using non-volatile memory. Example implementations ofnon-volatile memory based devices may include, but are not limited to,using NOR, NAND, MRAM (Magnetoresistive RAM), FRAM (Ferroelectric RAM,RRAM (Resistive RAM)), phase change memory or any other suitabletechnology. NOR flash may provide high-speed random access and readingand writing data in specific memory locations such as up to a singlebyte. NAND flash may read randomly but typically is written sequentiallyat high speed, handling data in small blocks called pages. NAND flashmay read faster than it writes, quickly transferring whole pages ofdata. NOR flash may behave in the same way except that reads may befaster than NAND flash and writes may be slower. Generally, lessexpensive than NOR flash at high densities, NAND technology may offerhigher capacity for the same-size silicon.

In some implementations, embodiments of the invention may utilize asingle-level cell (SLC) NAND flash technology. In other implementations,embodiments of the invention may utilize a Multi-Level Cell (MLC) NANDflash storage medium. MLC NAND is a flash memory technology usingmultiple levels per cell to allow more bits to be stored using the samenumber of transistors. In SLC NAND flash technology, each cell can existin one of two states, storing one bit of information per cell. Most MLCNAND flash memory technologies have four possible states per cell, so itcan store two bits of information per cell. Using MLC NAND may beadvantageous for reducing the cost of per unit of storage due to thehigher data density.

In certain embodiments of the invention, the system hardware, such asthe non-volatile memory is integrated with the vertically integratedsystem, therefore integrating the hardware and software solutions. Incontrast to prior art systems, in certain embodiments of the invention,the non-volatile memory is not implemented as part of several discreteblack-box devices purchased off the shelf or from original equipmentmanufacturers (OEMs). Instead, certain embodiments of the inventiondescribe developing a storage system from ground up where the storagehardware 202 is implemented as a single integrated system comprisingnon-volatile memory that is managed by a single software stack,comprising all the house-keeping functionality. In such a system onlyone instance of the house keeping functions, such as management,journaling, garbage collection, mapping, and system writecombining/caching may be needed for managing all of the non-volatilememory in the storage device.

The user interface at the application 222 is significantly simplifiedand integrated, providing the user with an integrated view of the systemhardware and software and knobs/hooks for globally managing allfunctions.

For compression 220, the integrated approach allows for a singlecompression operation for each transaction, improving performance andeffectiveness of the system, while storing data. This is in contrast toFIG. 1, where the compression algorithm is run in up to five or moredifferent layers (file system layer 112, snapshot layer 110 anddeduplication layer 108 and the compression layer 108) repeatedly withlittle to no additional benefit, since compressed data cannot becompressed much further. Block 220 may also perform decompression ofdata, when data is accessed from the storage medium.

Deduplication 218 functionality may use a dedup table, mapping table,garbage collection, and journaling for performing deduplication. In oneimplementation, the integrated approach discussed in this disclosureallows the deduplication functionality to reuse the shared garbagecollection 208, mapping tables 204, journaling 210 and garbagecollection 208. In some instances, the garbage collection 208, mappingtables 204, journaling 210 and garbage collection 208 functionality isimplemented in storage firmware (or FTL). Furthermore, in oneimplementation, the signature generation for deduplication may be, fullyor partially, performed at the same time data is compressed by thecompression module 220.

A vertically integrated implementation of the deduplication 218functionality, as an example, demonstrates the value of an integratedapproach. Generally, deduplication 108 functions by generatingsignatures using efficient hashing techniques for groups of data. Thesignatures are usually stored in a dedup table and/or mapping structuremaintained by the deduplication unit 108. In one implementation, foraccess requests for storing data, the storage device may use the sameefficient hashing technique on the data to be stored and generate asignature. The signature for the data associated with the store requestmay be matched against the signatures of groups of data already residingon the storage device using the dedup or/and mapping table. Matching ofthe signatures may indicate that the storage device already has a copyof the data matching the data to be stored on the storage device,therefore detecting the potential duplication of data. The storagedevice may instead of storing the duplicate data, may update the deduptable or/and the mapping structure to point to the duplicate data,therefore avoiding expensive write cycles. On read access request, themapping structure may appropriately route the access request for readingthe data to the appropriately stored data.

Traditionally to perform this function, data must be processed, on abyte or very small granularity, to generate the signature fordeduplication. FIG. 3 shows how the deduplication module 218opportunistically shares the common and optimized functionality providedby the integrated system. In a vertically integrated system, embodimentsof the invention may advantageously generate the signatures (as shown byblock 224) in the compression 220 module, at the same time data is beingcompressed. This is advantageous over the prior art techniques, sincecompression already processes the data once on a very small granularityto compress the data. Instead of reprocessing the data again fordeduplication for generating signatures again, the signatures can begenerated at the same time as compressing the data. In the prior art,such integration of steps is not possible since compression anddepulication are performed using different segmented layers provided bydifferent vendors and data is processed at least twice or many times,separately for the compression and deduplication functionality.Embodiments of the invention, by reducing the required processing, speedup the access request and also save power in the process.

Furthermore, maintaining of the dedup tables and/or mapping tables fordeduplicating data may be performed by the mapping module 206. In someembodiments, this may further save space and reduce the number ofaccesses to the underlying non-volatile medium by consolidating all theaccesses using a single mapping structure. Non-volatile memory isgenerally susceptible to rapid wear as compared to the traditional harddrives and reducing the number of accesses for non-volatile memory isimportant, since it reduces wear of the storage medium and increases thelife of the storage device. Moreover, for power failure, thededuplication module can use the journaling 210 functionality providedfor the integrated system. Similarly, for garbage collection and systemwrite combining/caching, in FIG. 3, the deduplication may use themapping 206 and system write combining/caching 204 functionality.

Similarly, a single management functionality 212 may manage the variousfunctionalities throughout the vertically integrated stack for storage.In one implementation, the management functionality provides theinterface for managing the various functionalities (204-220) throughoutthe vertically integrated stack for storage, such as providing the userwith controllability of the features, collection of diagnosis data andproviding interface for performing remedial and maintenance tasks.

Mapping 206 functionality provides the logical address to the physicaladdress translations. In one implementation of the integrated approach,components of the device 400 enable collapsing of the mapping for thedifferent functionality using a single multidimensional mappingstructure. For example, individually, the file system uses a2-dimensional mapping and the snapshot functionality uses a2-dimensional mapping. These two mapping structures may be collapsedinto a single 3-dimensional mapping structure. For example, onedimension of the multidimensional mapping structure may be representedby the File System ID and a second dimension may be represented by asnapshot version. Furthermore, as discussed with respect todeduplication 218, other system functionalities may also consolidatetheir mapping needs within the same mapping 206 functionality. This maybe advantageous since the mapping tables are large and multiple reads tothe mapping tables results in multiple data accesses to the storagemedium increasing the wear of the storage disk and adversely impactingthe latency of the read. For instance, in contrast to FIG. 2, in FIG. 1a transaction from the application layer may invoke a separate mappingstructure from almost every layer it traverses down the stack creatingmultiple accesses to the underlying hardware. In one implementation ofthe embodiments, the mapping is provided in the firmware layer.

The integrated approach also allows for a novel implementation of RAID214 with equivalent/similar robustness and availability characteristicsto RAID 6. Traditionally, RAID-5 requires two writes for each write andRAID-6 requires three writes for each write, each operating using thelogical addresses for the access requests. The multiple writes wearsdown the storage medium, especially non-volatile memory based storagedevices and also decreases performance of the system. In contrast, theintegrated approach enables the novel RAID implementation 214 to operateusing physical addresses instead of logical address allowing full stridewrites sequentially without Read Modified Write operations, resulting ina performance boost while also reducing wear on the flash products. Incertain implementation, the integrated approach enables RAID 214 tooperate using physical addresses after the mapping 206 is performed,since the mapping no longer is segmented and hidden in a black boximplementation of an HDD or SDD, allowing for such enhancements to theRAID 214 implementation.

In some implementation, house-keeping functions, such as garbagecollection 208, journaling 210 and mapping 206 may be performed onlyonce for the various different functionalities, shown in FIG. 2,therefore significantly reducing the overhead. For instance, in contrastto FIG. 2, in FIG. 1, journaling is performed at multiple levels of thestack since each level is architected independently and cannot rely onthe journaling capabilities of another layer. As described with respectto FIG. 2, in an integrated approach, journaling is performed only onceat a higher level to protect the state of the device againstcatastrophic events.

In some implementations, the functionality provided by the differentblocks (204-220) shown in FIG. 2 are provided by a single integratedmodule 224. It should be noted that the sequence of the functions and/ormodules shown in FIG. 2 is non-limiting and the functions and/or modulesmay be implemented in any sequence, without departing from scope of theinvention.

In some implementation, some of the functions are stored as executablecode/binary as firmware executable code in the storage hardware 202, andare executed using one or more Application Specific Integrated Circuits(ASIC), Field Programmable Gate Array (FPGA), or processing units. Forinstance, in one implementation, the garbage collection and mapping maybe performed by firmware. In one implementation, the variousfunctionalities described in FIG. 2 are integrated into a singleexecutable binary or executable code, stored on a storage medium andexecuted after loading into memory. In another implementation, thevarious functionalities from FIG. 2, although integrated may be loadedas modules of an executable codebase, such as a kernel. Some modules maybe loaded on a per-need basis, whereas other modules may stay persistentin memory. In yet another implementation, the vertically integratedmodules may be stored in separate locations in the device and may be runseparately, but may execute in an integrated manner. For example, thecompression functionality, deduplication functionality and the filesystem functionality may be implemented in software stored on thestorage medium and run on a processor, whereas the mapping functionalitymay be stored on the firmware flash and executed on a FPGA.

In one implementation, the system of FIG. 2 may be implemented in anenterprise environment for providing access to large amounts of storage.In one implementation, the storage hardware 202 may comprisenon-volatile memory. In one implementation, an array of non-volatilememory is used in implementing the storage hardware 202. In anotherimplementation, a large number of multi-level-cell flash chips, singlelevel cell flash chips or any other suitable storage medium may be usedin implementing the storage hardware 202 of FIG. 2.

Vertically integrating the functionality, as described in FIG. 2, hasseveral advantages. Vertically integrating the various functionalitiesof the multiple layers into a single layer significantly increases theability of the system to provide reliability, robustness and faulttolerance functions while improving storage capacity, power consumption,and latency of the overall system. As described, embodiments of theinvention, reduce/remove the interface bottlenecks between the variouslayers, reduce duplication of functionality in different layers thatprovide little or no added benefit, and reduce the footprint of theexecutable code. Many of these advantages result in more efficient useof processing power and electrical power, and also result in much loweraccess latencies for the storage device.

Furthermore, by reducing duplication of functionality and also tightlyintegrating the functionality of several modules, the number of accessesto the non-volatile memory may be significantly reduced. The importanceof reducing accesses to the memory is further pronounced fornon-volatile memory storage systems, since non-volatile memory isgenerally more susceptible to wear due to repetitive access as comparedto the traditional hard drives.

As described, modules described in FIG. 2 cannot be replaced withmodules described in FIG. 1, since the modules in FIG. 1 require varioushouse-keeping functionality such as journaling, caching, writecombining, mapping, and garbage collection implemented within eachsegmented layer and do not allow inter module access to such resources.In addition, in prior art systems, not only can they not share resourcessuch as journaling, caching, write combining, mapping, and garbagecollection across layers, most higher layers of the storage device donot even have visibility to such features implemented inside the SSDs.The vice-versa is also true, wherein a module or layer from a prior artsystem of FIG. 1 cannot replace a module from embodiments of theinvention, as described in FIG. 2.

Other advantages may include rapid development time, increased abilityto integrate innovation and reduced number of bugs in the system.

FIG. 4 is a flow diagram, illustrating a method for accessing andstoring data. The signaling in method 400 is performed by processinglogic that comprises hardware (circuitry, dedicated logic, etc.),software (such as is run on a general purpose computing system or adedicated machine), firmware (embedded software), or any combinationthereof. In one embodiment, the method 400 is performed by one or morecomputer systems 500 as described in FIG. 5.

At block 402, components of the device 500, receive data for storing onthe storage medium. At block 404, components of the device 400, performdata compression on the received data. In one implementation, thecompression algorithm may be performed only once between receiving dataand storing the data on the storage medium. At block 306, the data isdeduplicated, as discussed in FIG. 2. Deduplication of data may useunified procedures for garbage collection and mapping provided by thefirmware. At block 308, components of the device 500, may performsnapshots/cloning and/or thin provisioning of the data. At block 410,components of the device 500 may perform file system management tasks.At block 412, components of the device 500, may perform journaling ofthe system state for performing the store operation. Journalingfunctions may be provided only once in the software layers. At block414, components of the device 500 may perform linear to physicaltranslations for storing the data on the storage medium. At block 416,components of the device 500 may perform system write combining and/ordata coalescing. At block 418, components of the device 500 may storethe processed data on the storage medium. Although, not shown, incertain embodiments, the data may be spread across the storage mediumusing RAID techniques before storing the data. Embodiments of theinvention allow for RAID operations using the physical address of theaccess request rather than the logical addresses, resulting in reducednumber of writes.

It should be appreciated that the steps described above are for storingdata on the storage medium. However, accessing data from the storagemedium also may traverse through the same or similar steps in reverseorder and perform reverse functionality in some instances. For example,the mapping functionality 414 for the access request maps a linear tophysical, however, the compression block 402, performs decompression ofdata instead of compression for accessing data instead of storing data.

It should be appreciated that the specific steps illustrated in FIG. 4provide a particular method of switching between modes of operation,according to an embodiment of the present invention. Other sequences ofsteps may also be performed accordingly in alternative embodiments. Forexample, alternative embodiments of the present invention may performthe steps outlined above in a different order. To illustrate, a user maychoose to change from the third mode of operation to the first mode ofoperation, the fourth mode to the second mode, or any combination therebetween. Moreover, the individual steps illustrated in FIG. 4 mayinclude multiple sub-steps that may be performed in various sequences asappropriate to the individual step. Furthermore, additional steps may beadded or removed depending on the particular applications. One ofordinary skill in the art would recognize and appreciate manyvariations, modifications, and alternatives of the method 400.

Having described multiple aspects of the vertically integratedarchitecture, an example of a computing system in which various aspectsof the disclosure may be implemented may now be described with respectto FIG. 5. According to one or more aspects, a computer system asillustrated in FIG. 5 may be incorporated as part of a computing device,which may implement, perform, and/or execute any and/or all of thefeatures, methods, and/or method steps described herein. For example,computer system 500 may represent some of the components of a deviceand/or access point apparatus. A device may be any computing device witha wireless unit, such as an RF receiver. In one embodiment, the system500 is configured to implement any of the methods described herein. FIG.5 provides a schematic illustration of one embodiment of a computersystem 500 that can perform the methods provided by various otherembodiments. FIG. 5 is meant only to provide a generalized illustrationof various components, any and/or all of which may be utilized asappropriate. FIG. 5, therefore, broadly illustrates how individualsystem elements may be implemented in a relatively separated orrelatively more integrated manner.

The computer system 500 is shown comprising hardware elements that canbe electrically coupled via a bus 505 (or may otherwise be incommunication, as appropriate). The hardware elements may include one ormore processors 510, including without limitation one or moregeneral-purpose processors and/or one or more special-purpose processors(such as digital signal processing chips, graphics accelerationprocessors, and/or the like); one or more input devices 515, which caninclude without limitation a camera, a mouse, a keyboard and/or thelike; and one or more output devices 520, which can include withoutlimitation a display unit, a printer and/or the like. The computingdevice 500 may also include a sensor(s), such as temperature sensors,power sensors, etc. for monitoring health of the system.

The computer system 500 may further include (and/or be in communicationwith) one or more non-transitory storage devices 525, which cancomprise, without limitation, local and/or network accessible storage,and/or can include, without limitation, a disk drive, a drive array, anoptical storage device, a solid-state storage device such as a randomaccess memory (“RAM”) and/or a read-only memory (“ROM”), which can beprogrammable, flash-updateable and/or the like. In some embodiments, thestorage may be implemented using non-volatile memory. Such storagedevices may be configured to implement any appropriate data storage,including without limitation, various file systems, database structures,and/or the like.

The computer system 500 might also include a communications subsystem530, which can include without limitation a modem, a network card(wireless or wired), an infrared communication device, a wirelesscommunication device and/or chipset (such as a Bluetooth® device, an802.11 device, a WiFi device, a WiMax device, cellular communicationfacilities, etc.), and/or the like. The communications subsystem 530 maypermit data to be exchanged with a network (such as the networkdescribed below, to name one example), other computer systems, and/orany other devices described herein. In many embodiments, the computersystem 500 may further comprise a non-transitory working memory 535,which can include a RAM or ROM device, as described above. The computersystem 500 might also include a transceiver 1050 for facilitatingcommunication by the communications subsystem 530 with the externalentities.

The computer system 500 also can comprise software elements, shown asbeing currently located within the working memory 535, including anoperating system 540, device drivers, executable libraries, and/or othercode, such as one or more application programs 545, which may comprisecomputer programs provided by various embodiments, and/or may bedesigned to implement methods, and/or configure systems, provided byother embodiments, as described herein. Merely by way of example, one ormore procedures described with respect to the method(s) discussed above,might be implemented as code and/or instructions executable by acomputer (and/or a processor within a computer); in an aspect, then,such code and/or instructions can be used to configure and/or adapt ageneral purpose computer (or other device) to perform one or moreoperations in accordance with the described methods.

A set of these instructions and/or code might be stored on acomputer-readable storage medium, such as the storage device(s) 525described above. In some cases, the storage medium might be incorporatedwithin a computer system, such as computer system 500. In otherembodiments, the storage medium might be separate from a computer system(e.g., a removable medium, such as a compact disc), and/or provided inan installation package, such that the storage medium can be used toprogram, configure and/or adapt a general purpose computer with theinstructions/code stored thereon. These instructions might take the formof executable code, which is executable by the computer system 500and/or might take the form of source and/or installable code, which,upon compilation and/or installation on the computer system 500 (e.g.,using any of a variety of generally available compilers, installationprograms, compression/decompression utilities, etc.) then takes the formof executable code.

Substantial variations may be made in accordance with specificrequirements. For example, customized hardware might also be used,and/or particular elements might be implemented in hardware, software(including portable software, such as applets, etc.), or both. Further,connection to other computing devices such as network input/outputdevices may be employed.

Some embodiments may employ a computer system (such as the computersystem 500) to perform methods in accordance with the disclosure. Forexample, some or all of the procedures of the described methods may beperformed by the computer system 500 in response to processor 510executing one or more sequences of one or more instructions (which mightbe incorporated into the operating system 540 and/or other code, such asan application program 545) contained in the working memory 535. Suchinstructions may be read into the working memory 535 from anothercomputer-readable medium, such as one or more of the storage device(s)525. Merely by way of example, execution of the sequences ofinstructions contained in the working memory 535 might cause theprocessor(s) 510 to perform one or more procedures of the methodsdescribed herein.

The terms “machine-readable medium” and “computer-readable medium,” asused herein, refer to any medium that participates in providing datathat causes a machine to operate in a specific fashion. In an embodimentimplemented using the computer system 500, various computer-readablemedia might be involved in providing instructions/code to processor(s)510 for execution and/or might be used to store and/or carry suchinstructions/code (e.g., as signals). In many implementations, acomputer-readable medium is a physical and/or tangible storage medium.Such a medium may take many forms, including but not limited to,non-volatile media, volatile media, and transmission media. Non-volatilemedia include, for example, optical and/or magnetic disks, such as thestorage device(s) 525. Volatile media include, without limitation,dynamic memory, such as the working memory 535. Transmission mediainclude, without limitation, coaxial cables, copper wire and fiberoptics, including the wires that comprise the bus 505, as well as thevarious components of the communications subsystem 530 (and/or the mediaby which the communications subsystem 530 provides communication withother devices). Hence, transmission media can also take the form ofwaves (including without limitation radio, acoustic and/or light waves,such as those generated during radio-wave and infrared datacommunications).

Some embodiments may employ a computer system (such as the processor510) to perform methods in accordance with the disclosure. For example,some or all of the procedures of the described methods may be performedby the viewing apparatus in response to the processor executing one ormore sequences of one or more instructions (which might be incorporatedinto an operating system and/or other code, such as an applicationprogram) contained in working memory. Such instructions may be read intothe working memory from another computer-readable medium, such as one ormore of the storage device(s). Merely by way of example, execution ofthe sequences of instructions contained in the working memory mightcause the processor(s) to perform one or more procedures of the methodsdescribed herein.

Again, embodiments employing computer systems described herein are notlimited to being physically connected to the viewing apparatus.Processing may occur in another apparatus, connected via wire orwirelessly to the viewing apparatus. For example, a processor in a phoneor instructions for executing commands by a phone or tablet may beincluded in these descriptions. Similarly, a network in a remotelocation may house a processor and send data to the viewing apparatus.

The terms “machine-readable medium” and “computer-readable medium,” asused herein, refer to any medium that participates in providing datathat causes a machine to operate in a specific fashion. In an embodimentimplemented using the processor 510, various computer-readable mediamight be involved in providing instructions/code to processor(s) 510 forexecution and/or might be used to store and/or carry suchinstructions/code (e.g., as signals). In many implementations, acomputer-readable medium is a physical and/or tangible storage medium.Such a medium may take many forms, including but not limited to,non-volatile media, volatile media, and transmission media. Non-volatilemedia include, for example, optical and/or magnetic disks. Volatilemedia include, without limitation, dynamic memory, such as flash memoryor DDR3 RAM. Transmission media include, without limitation, coaxialcables, copper wire and fiber optics, as well as the various componentsof a communications subsystem (and/or the media by which thecommunications subsystem provides communication with other devices).Hence, transmission media can also take the form of waves (includingwithout limitation radio, acoustic and/or light waves, such as thosegenerated during radio-wave and infrared data communications).

In one or more examples, the functions described may be implemented inhardware, software, firmware, or any combination thereof. If implementedin software, the functions may be stored on or transmitted over as oneor more instructions or code on a computer-readable medium.Computer-readable media may include computer data storage media. Datastorage media may be any available media that can be accessed by one ormore computers or one or more processors to retrieve instructions, codeand/or data structures for implementation of the techniques described inthis disclosure. “Data storage media” as used herein refers tomanufactures and does not refer to transitory propagating signals. Byway of example, and not limitation, such computer-readable media cancomprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage,magnetic disk storage, or other magnetic storage devices, flash memory,or any other medium that can be used to store desired program code inthe form of instructions or data structures and that can be accessed bya computer. Disk and disc, as used herein, includes compact disc (CD),laser disc, optical disc, digital versatile disc (DVD), floppy disk andblu-ray disc where disks usually reproduce data magnetically, whilediscs reproduce data optically with lasers. Combinations of the aboveshould also be included within the scope of computer-readable media.

The code may be executed by one or more processors, such as one or moredigital signal processors (DSPs), general purpose microprocessors,application specific integrated circuits (ASICs), field programmablelogic arrays (FPGAs), or other equivalent integrated or discrete logiccircuitry. Accordingly, the term “processor,” as used herein may referto any of the foregoing structure or any other structure suitable forimplementation of the techniques described herein. In addition, in someaspects, the functionality described herein may be provided withindedicated hardware and/or software modules configured for encoding anddecoding, or incorporated in a combined codec. Also, the techniquescould be fully implemented in one or more circuits or logic elements.

The techniques of this disclosure may be implemented in a wide varietyof devices or apparatuses, including a wireless handset, an integratedcircuit (IC) or a set of ICs (e.g., a chip set). Various components,modules, or units are described in this disclosure to emphasizefunctional aspects of devices configured to perform the disclosedtechniques, but do not necessarily require realization by differenthardware units. Rather, as described above, various units may becombined in a codec hardware unit or provided by a collection ofinteroperative hardware units, including one or more processors asdescribed above, in conjunction with suitable software and/or firmwarestored on computer-readable media.

Various examples have been described. These and other examples arewithin the scope of the following claims.

What is claimed is:
 1. A storage device comprising: a storage mediumcomprising non-volatile memory; one or more processing entitiesconfigured to: execute a deduplication module to detect duplicity ofdata; and execute a Redundant Array of Independent Disks (RAID) moduleto provide fault tolerance by spreading data and parity informationacross the non-volatile memory; and the storage device is furtherconfigured to perform a journaling function using a journaling moduleonly once for the deduplication module and the RAID module for an accessrequest to the storage medium on the storage device; and perform amapping function using a mapping module only once for the deduplicationmodule and the RAID module for the access request to the storage mediumon the storage device.
 2. The storage device of claim 1, wherein a flashtranslation layer (FTL) module comprises the journaling module and themapping module.
 3. The storage device of claim 2, wherein storage deviceis configured to execute a single instance of the FTL module for thestorage device.
 4. The storage device of claim 1, wherein the one ormore processing units are further configured to execute a compressionmodule for compressing data before storing the data on the storagemedium and decompressing the data after retrieving the data from thestorage medium, wherein the compression module does not have a separatejournaling functionality or separate mapping functionality.
 5. Thestorage device of claim 1, wherein the one or more processing units arefurther configured to execute a snapshot and thin provisioning module,wherein the snapshot and thin provisioning module does not have aseparate journaling functionality or separate mapping functionality. 6.The storage device of claim 1, wherein the one or more processing unitsare further configured to execute a File System (FS) module forproviding abstraction to an application for storing, retrieving andupdating files comprising data on the storage medium, wherein the FSmodule does not have a separate journaling functionality or separatemapping functionality.
 7. The storage device of claim 1, wherein the oneor more processing units are further configured to execute an OperatingSystem (OS) module configured to execute on one or more processors,wherein OS module does not have a separate journaling functionality orseparate mapping functionality.
 8. The storage device of claim 1,wherein the one or more processing units are further configured toperform a caching function using a caching module only once for thededuplication module and the RAID module for the access request to thestorage medium on the storage device.
 9. The storage device of claim 1,wherein the one or more processing units are further configured toperform a garbage collection function using a garbage collection moduleonly once for the deduplication module and the RAID module for theaccess request to the storage medium on the storage device.
 10. Thestorage device of claim 1, wherein the mapping function by the mappingmodule performs a translation from a linear address to a physicaladdress for the access request to the storage device using amultidimensional mapping, wherein a first dimension of themultidimensional mapping is a file identifier and the second dimensionof the multidimensional mapping is a snapshot version.
 11. Anon-transitory computer readable storage medium, wherein thenon-transitory computer readable storage medium comprises instructionsexecutable by a processor, the instructions comprising instructions to:manage access to the non-volatile memory for the storage medium using aFlash Translation Layer (FTL) module; detect duplicity of data using adeduplication module; provide fault tolerance by spreading data andparity information across the non-volatile memory using a RedundantArray of Independent Disks (RAID) module; perform a journaling functionusing a journaling module only once for the FTL module, thededuplication module and the RAID module for an access request to thestorage medium on the storage device; and perform a mapping functionusing a mapping module only once for the FTL module, the deduplicationmodule and the RAID module for the access request to the storage mediumon the storage device.
 12. The non-transitory computer readable storagemedium of claim 1, wherein the instructions are part of a singleexecutable binary.
 13. The non-transitory computer readable storagemedium of claim 1, further comprising instructions to compress data onlyonce for a store access request and decompress data only once for a readaccess request.
 14. The non-transitory computer readable storage mediumof claim 1, further comprising instructions to perform caching functiononly once for the access request to the storage medium on the storagedevice.
 15. The non-transitory computer readable storage medium of claim1, further comprising instructions to perform garbage collectionfunctionality only once for the access request to the storage medium onthe storage device.
 16. A method for accessing a storage medium on astorage device, the method comprising: managing access to thenon-volatile memory for the storage medium using a Flash TranslationLayer (FTL) module; detecting duplicity of data using a deduplicationmodule; providing fault tolerance by spreading data and parityinformation across the non-volatile memory using a Redundant Array ofIndependent Disks (RAID) module; performing a journaling function onlyonce using a journaling module for an access request to the storagemedium on the storage device; and performing a mapping function onlyonce using a mapping module only once for the access request to thestorage medium on the storage device.
 17. The method of claim 16,further comprising compressing data only once for a store access requestand decompressing data only for a read access request.
 18. The method ofclaim 16, further comprising performing caching only once for the accessrequest to the storage medium on the storage device.
 19. The method ofclaim 16, further comprising performing garbage collection functionalityonly once for the access request to the storage medium on the storagedevice.
 20. The method of claim 16, further comprising performinggarbage write combining only once for the access request to the storagemedium on the storage device.